Perhaps you should try some spelling variations:
hanh trinh » canh tranh, hanh chinh
hieu lang » chieu sang, hieu quang, nhieu tang
cua khong » cua phuong, cua thuong, cua cong
hua khong » hoa khong, hoac khong, phuc khong
hoi hieu » hoi phieu, hoi tieu, moi hieu
tam toan » tap toan, tam than, pham toan
ta toan » tap toan, va toan, ta tuan

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: hoi hieu lang - hanh trinh ((cua khong) OR (hua khong)) cung ((ta toan) or (tam toan)) ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoi hieu lang - hanh trinh ((cua khong) OR (hua khong)) cung ((ta toan) OR (tam toan)) ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoi hieu lang - hanh trinh ((cua khong) OR (hua khong)) cung ((ta toan) or (tam toan)) ban".
• Adding a wildcard symbol may retrieve word variants: hoi hieu lang - hanh trinh ((cua khong) OR (hua khong)) cung ((ta toan) or (tam toan)) ban*.